Flexible diaphragm for gas meters



July 11, 1950 E. R. GILMORE 2,514,388

FLEXIBLE DIAPHRAGM FOR GAS METERS Filed Oct 27, 1944 3 Sheets-Shet 1 Edward R. Gilmore m MMQ X u y 1950 E. R. GILMORE 2,514,388

FLEXIBLE DIAPHRAGM FOR GAS METERS FiledOct. 27, 1944 3 Sheets-Sheet? 5 74 7a 5 72 8i i 8 2 1 o 8 c L F 66 g 76 542 A as 48 4 42 5 34- s so 34 4 3s E. u 1 E .E 36 1 s4 32 v f '4 32 FIG. 5 4Q FIG. 6

as as W INVENTOR. 3a 4 EDWARDR. GILMORE FIG. 7 4 BY WWW ATTORNEYS y 1950 Y E. R. GILMORE 2,514,388

FLEXIBLE DIAPHRAGM FOR GAS mamas Filed 001;. 27, 1944 s Sheets-Sheet s INVENTOR. EDWARD R. GILMORE ATTORNEYS Patented July 11, 1950 TED STATES PATENT orries .Edward. R. Gilmore, Pittsburgh, Pa., iassignor to LIRockwell Manufacturing Company,Pitts'burgh, 2a,, a corporation of Pennsylvania .ApplicationzOctober=27, 1944, Serial N0.:5.60',655

This invention relates :to an improvedfiexible .diaphragm structure, the present improvement being more particularlydesigned for .use in the operation of gas consumption recording :meters, and the subject matter of :the present applicaition constituting a .continuation-in p-art of the disclosure .of a diaphragmtof this type described and claimed in my co-pending application for vpatent, Serial No. 448,601, filed-June 26,1942, :nowabandoned.

,-It is the major-object of this invention-taprovide a diaphragm for ,gas meters and other .apparatus having certain (novel features of construction .and assembly of its several elements :whereby the flexible'diaphragmis. effectively sustained against-collapse in thepnlsating action of i'the diaphragm and the functionally effective-life thereof materially prolonged.

,-In prior .artaefiorts tolsolve this problem in the gas meter field various methods have beensug- .ggested for attaching the diaphragm leather to the inner and .outer relatively movable metallic sections of the diaphragm structure with a view to: minimizing thedeleterious .efiectsiof flexing or bendin stresses in the leather as one of said asections, subject to differential gas pressures, .al- .ternately moves to positions .-,at opposite sides of the plane of theiother.diaphragmsection. How- .ever, suche'fiorts have failed to fullymeet requirements, as .the :free ,intermediatetsection .of .-the diaphragm leather is not adequately sustainedzaga'inst collapse, and, :in the pulsating ac- :tion ,either :re-verses its curvature .or is distorted .froma.substantiallystraight lineconditionat one .end of the diaphragm stroketo a more or .less

rolling action of :said membrane is obtained in in the pulsating stroke of :the diaphragm which, in :all positions thereof, is-adequatelyself-sus- 'tained uagainst collapse, and the severe i-bending, flexing or tensile estrains, common to the priorart devices, are substantially eliminated. :In .;-func- 1 .tionalorieration a substantially-larger effective characters displacement .of the pressure responsive area of the diaphragm is obtained, .in-lcomparlson-with .a conventional diaphragm,.for the same ,length .ofstroke.

. Another ,object oftthe invention is to provide an outer mounting .member for the diaphragm -.of improved structural form .to which the outer edge of the .fiexible diaphragm membrane is attached and which will materially aid in sustaining said imembrane against collapse during the operatingstroke of .the diaphragm.

;.It .is also additional object 1 of the, invention ,t0 provide.an. inner diaphragm section comprising metallic disks-between which the central .porvtien .of the, flexible .leather .or -.=membrane sis .se- :curely clamped, the peripheral edge portions-of :said disks being .so constructed and related to leach tether .that the wall of the membrane extending outwardly therebetween may have free .ra'dial .movementrelative to said peripheral portions of the disks, thus obviating sharp bending or .flexingstrains in the pulsating stroke :01 :the diaphragm.

My invention also comprehends a movel ,pre vformedflex-ible leather .or membrane .to provide ;a comparativelyself-sustaining impervious :area thereof, subject to the gas pressure, having :a predetermined gradual curvature axially 10f the diaphragm and in which there vzill 'occur arminimumza-lteration of such curvature in :the operating :stroke of the diaphragm.

.Having'the above and other subordinate zeb- ,,,j:ects in view, in the accompanyingtdrawings 1-1 have illustrated onesimple andgpracticalembodi- .ment of my present invention, vvhich v.willhereinafter bemorefully described and the several novel features thereof subsequently :defined in :the subj'oined claims.

:In :the drawings, .in which similar reference designate corresponding parts throughout the-several views:

7 Figure l'is a vertical section, partly in elevation, showing an extreme position of the'diaphragm leather;

FfgureZ risa side elevation;

"Figure 3 is a fragmentary sectional "viev'v, illustrating'lthe rolling action of thediaphragm leather;

, Figures 4, .15 andj6. are vertical sectional views progressively illustrating the several method-steps in pre-formin the diaphragm .by vmeans of one suitable type of apparatus;

.Eigure fl is an enlarged fragmentary sectional view of the diaphragm clamping arrangement of the apparatus of Figures 4-6; and

Figure 8 is a diagrammatic view illustrating the increased eifective displacement of my new diaphragm in relation to the displacement of a conventional prior art diaphragm.

With more particular reference to the drawings, for the purpose of this explanation, I have selected an example of my invention which embodies three primary sections comprising the outer fixed supporting section or diaphragm pan it, the inner movable section or pressure receiv-, ing head H, and the connecting flexible membrane, usually leather, section 12 attached to said inner and outer diaphragm sections. This general construction is, of course, characteristic of diaphragm structures of this type.

The outer section or pan in of the diaphragm, structure includes an outwardly flaring circum ferential wall l3, the edge of which is outwardly bent to form an open bead l4, from which a concave-convex annular flange l extends towards the base of the pan and has its concave face outwardly disposed. The free edge of this flange and the outer peripheral surfaceof the head 14 are substantially tangential to a common horizontal plane. The particular advantage of this construction in the functional operation of the diaphragm will be hereinafter more fully explained.

To the outer surface of the pan wall [3, a suitably formed attaching bracket 16 is securely fixed and is adapted to be rigidly attached to the gas chamber wall of the meter. In circumferentially spaced relation from this bracket the wall I3 is also provided with a short outwardly extending conduit section II provided with suitably formed means atits end whereby it may be connected in coupled relation with the end of a conduit on the gas chamber wall so as to permit the gas flow through the customary channels of the meter -casing.

While in the present instance I have shown this outer section Ill of the diaphragm structure in the form of a pan, it is to be understood that this section may also be embodied in the form of an annular metal plate having the flange l5 onits inner edge, as suggested by my co-pending application.

The diaphragm membrane I2 is preferably formed from a sheet of sheepskin, or any other suitable material having comparable flexible or pliable characteristics. In order that the purposes of my present invention may be fully attained it is essential that the area of the leather sheet, between its points of attachment to the outer and inner sections I 0 and H of the diaphragm. structure, be pre-formed to a predetermined shape, designed to render the area substantially self-supporting and resistant to col lapse during flexure in normal operation, and in which area the originalflexibility of the leather preferably remains substantially unaltered.

In Figures 4 to 7 of the drawings I have illustrated one embodiment of apparatus for producing a pre-formed diaphragm as above characterized, As therein shown, a fixed female die member 32 is rigidly mounted between spaced vertical guides 34 extending above said die member. The member 34 includes an outer cylindrical wall inft'egrallyconnected at its upper end to the inwardly and downwardly conically tapering wall 35 by the annular, horizontal work supporting seat 38. v y

A male die carrying member is vertically mov- 7 4 able between the guides 34 above the fixed die member 32 and includes the cylindrical vertical wall 40 and a horizontal top wall 42, said member being open at its lower end to telescopically receive the cylindrical work clamping ring 44. At diametrically opposite points on the wall 42, spring housings 46 are suitably secured. To the upper ends of these housings rods 48' are fixed and extend'do'wnwardly therefrom through openings in inwardly projecting lugs 50 formed on the upper edge of the ring 44. Springs 52 bear Y at their lower, ends against these lugs and at such movement of the ring being limited by heads 54 formed on the lower ends of the rods 48.

The male die preferably comprises a hollow bulbous member having a substantially semispherioal lower end portion 56, preferably formed with a flat bottom face 58, and an inwardly tapering intermediate' portion 6U merging into the cylindrical upper end portion 62 of reduced diameter, which is suitably fixed to the lower face of the top wall 42 of the die carrying'member in concentric relation with the cylindrical wall 40 thereof.

A frame member 64 has'spaced vertical legs 66 suitably fixed to a suitable supporting base and a horizontal connecting portion 68 between the upper ends of said legs, extending diametrically across the maledie carrying member and vertically spaced therefrom. 'In a collar 10 centrally fixed to the frame-portion 68, an adjusting screw 12 is threaded. Screw 12 is provided at its upper end with a suitable operating handle member 14 and at its lower end has a swiveled or rotatable connection 75 with the top wall 42 of the male die carrying member.

Preferably, suitable means is provided to limit the downward movement of themale die carrying member. As herein shown I provide the rod 18 fixed to said member and vertically movable through an opening in the frame 64. Upon the frame, a pivoted stop plate is mounted and yieldingly urged by the spring 82 to engage a stop shoulder 84'formed on the rod 18.

, For the purpose of {increasing the ironing effectiveness of the clamping ring 44, I preferably form a shallow annular groove 86 in the lower edge face thereof adjacent to its inner cylindrical surface, said edgeface being curved or tapered upwardly and radially outwardly from said groove to the outer cylindrical surface of the ring, as shown at 88 in Figure '7 of thedrawings. Y e

In each operation of the above described apparatus, I preferably form a plurality of the diaphragm members, The flat circular sheets 90 of leather or other flexible material of uniform thickness and of requisite surface area to form diaphragms of a predetermined diameter are first thoroughly dampened with a mixture of alcohol and water. They are then assembled in superimposed relation and positioned with their marginal edge portions supported on the seat 38 of the female die member 32, as shown in Figure 4. Preferably, the de-haired' side of the sheet is uppermost and in the finished diaphragm is on the outer side. In this figure the adjusting screw 12 has been operated to'move the male die carrying member and ring 44 downwardly as a unit and position the bottom face'58 of the male die immediately above the central portions of the assembled sheets QB-and'the lower edge of ring in a meter.

44,substantial y.in-eontaet w h-. he margina rn tion .of the upperm stz h etll oniu h rop ra i n o h a ju ti sc ew,

the male ie audi arrying member a mo dow ard re tiv t t e rin -4. the bottom ;-f-ace 58'of the male die engaginganddepressing the central area of the flexible sheets into the female die. Simultaneouslysprings}? are comres e -t e i nt rforce the rin 44 downwardlyand causelits loweredge facelto apply a .proer s r lvi c as nin gu ding "pressure upon the mar inal ed e porti ns of th sheets, asshown in Figures-,5 and 6 of the drawings, and the sheets are drawn -,over shaping edge 39 of the female die member. ,The pressure of ring 44 on the leather is only gsufiicient to prevent creases or'wrinkles from forming in the leather sheet at :the inner ;side of said ring in the depressionof the made ;1die-;member and :is

not sufficient to .tensionally strain or stretch the leather.

As the male die ismoved from the position of Figure 5 to that shownin Figurefi, the springs .52 are further compressed :and the marginal ,portions of the sheets ,90 drawn inwardly against the increasing resilient pressure resistance of the:ring 44 as said sheets fold inwardly inan arc of progressivelydecreasing radius and finally assume an arcuate cross-sectional form molded about and corresponding to that of the semispherical portion ,56 of the die member. This preforming operation produces the rather surprising result that under the preforming molding and ironing pressures the annular periphery of the sheet from which the diaphragm is formed is contracted in diameter, compacted and thickened slightly, constricting the material of the central portion of the diaphragm causing the excess material to form into a concave-convex annular or semi-spherical section of-the diaphragm,

self-sustaining and non-collapsing in operation Thus as seen in Figure 3, in the pulsatingstroke of the head H, in all positions thereof relative to "the pan l0, this intermediate annular area A of the diaphragm extends in a large radius arcbetween the head II and rim l5 and in the same lateral direction relative thereto .without abrupt :change in curvature. While the changes which may occur in the physical structure of the diaphragm membrane or sheet to render .the area A thereof self-sustaining arenot known, such alteration or transsure ring 44 andmoldedagainst the convex surface of plungerGO. Owing to the moist condi- =tion.of the sheet, in this ironing action the individual fibres of the sheet are re-distributed and crowded together thus producing a substantial- -lycircumferentially uniform radial increase in density of the sheet structure as the constricted peripheral section decreases in diameter. This increase in density is accompanied by a slight increase in thickness, and by measurement it has been found that this increase in thickness and density in the diaphragm membrane .pro-

gresses from the central region thereof to its marginal constricted section.

It will further be noted from reference to Figure :6 that the downward movement of the male .die is so limited that the .space between the portion '56- thereof and the wall 531: of the female die 3 2 is always greater than the aggregate thicknessof the several fiexiblesheetsso that the arcuately curved portions of the sheets are not compressed between the twodie members but are moulded snugly against the semi-spherical surface of male ,die. Thus, Joy'carefully controlling the movement of the ,male die member,

the flexible sheets are pre-formed without being subjected to appreciable tensile strain, and are maintained in a semi-spherical form free of wrinkles.

Preferably the predetermined axial curvature of the male die is substantially semi-spherical and-this is theshape into whichtheannular area of the diaphragm sheet between thefendregion clamped ,at 18 and the region of beginning 0f curvature indicated at 30 ismoulded by the above described operation. When the leather sheets are removed from the mold andseparated,

after having been dried, the compressed and moulded area-of each, between regions 18 fand 3G, and identified at A has such substantially semi-spherical curvature in axial cross-section as illustrated in the lower part ofFigure 1.

The diaphragm area A has substantially ,its

original flexibility after the above described forming operation, any small increase in stiff,- ness of the diaphragm materialas aresult of compression in the forming operation beingmore than compensated for bythereduced resistance to ,fiexure during operation resulting from the smooth rolling action provided by the specially pre-formed shape of the ,diaphragm.

,Of course when the formed leather sheet is operatively attached to the inner and outer sections of the diaphragm ;assembly,,in the :functional operation thereof, the area A does not assume the original curved form shown in Figure 1, but is maintained .in a somewhatpdistorted shape gasillustrated in Figure ,3. This distortion,

and preventing the closing of the pores .in :the

leather by the customary oil treatment. Thefinal treatment of the leather in an oilbath completely closes all pores therein and renders the same impervious to the passage of gas .therethrough.

After the pre-forming of the leather sheet as above described, the outer edge portion thereof is trimmed off, and the outer marginal part of the pre-formed area A of the sheet is then seated upon the concave face of the =flange.:l5:o'f the pan section H! of the diaphragm and securely fixed thereto by the binding string, as indicated at it, tightly wrapped about said marginal portion of the sheet and having the ends thereof tied or otherwise securely fixed to the clipmem her it. rigidly attached to the pan wall 13.

The inner or central area'B of the-diaphragm leather, which remains in its original compara tively soft, pliable condition, is tightly clamped between the outer and inner metal disks L9- and 20, respectively. These disks are preferablylof sheet metal of a suitable gauge, and :the outer disk I!) is formed with an outwardly turned peripheral beadf I. "The inner disk to isofrsomewhat greater diameter than the .outerldisk and has an outwardly vflaringx-marginal flange-.22 :ii'n

the plane of, and radially spaced from, the bead 2| on the disk I9. At its edge, the flange 22 is formed with the outwardly turned cylindrical bead 23.

While any preferred means might be employed to rigidly connect the'two disks l9 and 20 and securely clamp the leather therebetween, I have shown for this purpose a central threaded bolt anism of the meter, whereby in the pulsating movements of the diaphragm sections H and 12, resulting from unbalanced fluid pressures on opposite sides thereof, said operating mechanism will be operated in the usual manner.

Reference should now be had to Figure 3 of the drawing, wherein I have illustrated the rolling action of the pre-iormed free portion A of the diaphragm leather I2 in the pulsating stroke of the diaphragm. It will first be noted therefrom that in the movement of the inner diaphragm section II, from the position shown in full lines to the broken line position at the end of the stroke at the extreme left, there is no change in axial direction of the inner part of said diaphragm leather attached to the section H, but at both ends of the stroke the leather extends in the same direction from the outer periphery of the flang 22 and is not reversely turned Over the head 23 on said disk. Also in this movement of the diaphragm section H, it will be apparent that owing to the spaced relationship between the flange 22 of the inner disk and the bead 2| on the outer disk, the part of the leather extending therebetween has free radial movement so that it is not subjected to sharp bending or flexing strains.

Secondly, the curved flange l5 and bead 14 on the fixed pan member it), over which the edge portion of the pre-formed section A of the leather is positioned and secured, materially aids in sustaining the leather against collapse, this construction, in connection with the relatively compact fibre structure of' the adjacent portion of the pre-formed diaphragmsection A, effecting a distribution of the flexing of the leather over a longer radius curve in the stroke of the diaphragm than would be possible in the use of a conventional diaphragm having the marginal portion of the leather held or clamped between two flat surfaces. Thus, as will be seen from the drawing, at the points adjacent the connection of the leather with the inner and outer diaphragm sections, the leather, at all times, extends in the same axial direction from said sections and little flexing or bending of the leather occurs in the movement of the inner section II of the diaphragm structure from one end to the other of its stroke. It is at these points that structural deterioration and breakage or failure of the diaphragm leather, as used in prior art devices of this type, has most frequently occurred. In contradistinction, it will be seen that in the operation of the present invention only a gentle rolling action of the diaphragm leather takes place, which, throughout the pulsating stroke of the diaphragm, is adequately supported against collapse, and in which there is no reversal of curva ture or marked change in the cross-sectional configuration of the diaphragm leather to cause severe flexing or bending strains and the rapid ultimate destruction of the leather. I have found that by so pro-forming the leather 12 increased displacement by the diaphragm is obtained and the pulsating stroke of the diaphragm may be reduced in length with respect to the customary practice in this art, thus further reducing the destructive effects of bending of flexing strains. The invention also provides improved accuracy in-calibr'ation because of the ability of the diaphragm to undergo the same sequences of flexure with each stroke.

The substantial increase in effective displacement of thepressure responsive area of my new diaphragm membrane over that of the conventional non-processed membrane of the prior art, having a pulsating stroke of equal length, is graphically illustrated in Figure 8 of the drawings. Referring thereto, the lines l8 and 30, respectively, indicate the perimetrical portions of the outer mounting member and the inner movable pan between which the pressure responsive section of the flexible membrane extends. The inner and outer ends of the stroke of the movable pan are indicated at D and E, respectively. A plane perpendicular to the diaphragm stroke and coincident with the attached outer edge of the flexible membrane at 18 is indicated by the line K. Between the lines 18 and 30 the change in cross-sectional configuration of a conventional diaphragm in the outstroke of the inner pan member is shown at F, the volumetric displacement thereof being represented by the shaded area G.- Similarly, lines H represent the crosssectional configuration of my improved diaphragm membrane at the inner and outer ends of the stroke while the shaded areas J plus G indicate the volumetric displacement thereof. It will be noted that, although the two diaphragms have substantially the same surface area, owing to the fact that the diaphragm of this invention has a smooth continuous rolling flexure in one direction and does not reverse its curvature or assume a straight line condition between the point E and line l8 at the outer end of the stroke, a much greater volumetric displacement is obtained than is possible in the operation of the conventional or standard type of diaphragm. Comparative tests have shown that this increase in volumetric displacement is at least as great as twelve per cent.

From the above description and accompanying drawings the several novel features of my present disclosure and the advantages thereof in practical operation will be readily understood. It will be appreciated that by means of my improvements I have succeeded in materially reducing the flexure or distortion of the diaphragm leather and the destructive effects thereof, while at the same time obtaining maximum accuracy and reliability in the functioning of said diaphragm for the operation of the recording meter. It is evident that these novel features of my present invention may be embodied in diaphragm structures of various sizes and designed for other uses than in connection with gas meters- The above described method of pro-forming the diaphragm leather may, of course, be carried out with the use of molding or blocking forms of various conventional or well known types, and while I have specifically referred to the manner in which this method is employed in pre-formins a plurality of diaphragms or leathers, in some instances, a single leather diaphragm or sheet may be simultaneously pre-formed in a single operation of the molding apparatus.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A pre-formed diaphragm membrane comprising a circular sheet of fibrous non-elastic flexible material having a moulded, self-sustaining annular section of uniform arcuate crosssectional configuration in all planes diametrically bisecting said sheet with a substantially uniform progressive increase in density and thickness of the fibrous structure from the inner to the outer perimeter of said annular section.

2. A gas meter diaphragm membrane comprising a single non-elastic sheet of sheep-skin or the like having an inner region thereof characterized by a substantially uniform fibre distribution throughout said region and a self-sustaining molded annular section circumscribing said inner region and normally having a substantially quadrant-shaped arcuate curvature in radial cross section, said annular section bein characterized by increased density of its fibrous structure with respect to said inner region, progressively decreasing from its outer marginal portion to said inner region of the membrane.

3. The diaphragm membrane defined in claim 2 wherein said outer marginal portion comprises a diametrically constricted, compacted and thickened supporting section for said quadrantshaped section normally disposed in a circumscribing plane substantially parallel with the plane of said inner region.

4. Diaphragm structure for gas meters and the like including an outer fixed annular memher, a pulsatory inner member movable through said outer member between end positions materially spaced in opposite directions from the plane of said outer member, and a flexible connecting membrane attached to said members, comprising a single sheet of non-elastic fibrous material having an annular unattached portion of progressively increasing fibre density and resistance to flexing stress to the outer attached margin of said membrane, and operating to sustain said membrane in curvilinear cross-sectional form convex in one direction in all positions of said inner member.

5. In a diaphragm assembly for a gas meter, a relatively stationary pan having an annular outer rim, an instrument connected head adapted for pulsatory movement through said rim between end positions materially spaced in opposite directions from said rim, and a connecting flexible membrane comprising a single sheet of flexible non-elastic material having its central portion clamped to said head, an annular outer region secured upon said rim and an intermediate free annular portion preformed to convex cross section and to have progressively increasing material density outwardly to said outer region adjacent said rim so that said intermediate membrane portion maintains convexity in the same direction during the entire range of pulsatory movement of said head.

EDWARD R. GILMORE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 83,113 Tufts Oct. 13, 1868 521,745 Viney June 19, 1894 546,947 Viney Sept. 24, 1895 644,611 Konopinski Mar, 6, 1900 1,386,601 Crossett Aug. 9, 1921 1,472,744 Butler et al. Oct. 30, 1923 1,704,676 Berry Mar. 5, 1929 1,892,513 Goldkamp Dec. 27, 1932 1,898,253 MacLean et al. Feb. 21, 1933 2,033,354 Pennington Mar. 10, 1936 2,313,515 Brown Mar. 9, 1943 2,380,983 Mock Aug. 7, 1945 FOREIGN PATENTS Number Country Date 8,768 Australia 1932 19,731 France Mar. 13, 1915 (Addition to No. 426,677)

101,286 Australia June 8, 1937 350,005 France June 20, 1905 429,890 Germany June 7, 1926 438,473 Great Britain Nov. 18, 1935 

